1. Field of the Invention
The present invention relates to a method of recovering a coolant, to an apparatus therefor, to a tool therefor and to a three-way valve for recovering a pressurized fluid. More specifically, the invention relates to a simple method of recovering a coolant by utilizing a compressor in a refrigerator circuit such as an air conditioner of an automobile from which the coolant is to be recovered, to an apparatus therefor, as well as to a three-way valve for recovering a pressurized fluid, which opens or closes the valve unit upon manipulating a socket or a plug in a coupler unit.
2. Prior Art
Organizations such as WHO have heretofore been warning a relationship between an increase in the skin cancer and an increase in the amount of ultraviolet rays due to a decrease in the ozone layer in the polar regions.
One of the culprits can be attributed to an increased concentration of the freon gas in the atmosphere. Therefore, a strict limitation has been imposed on the release of the freon gas into the air.
Under such circumstances, it is becoming an indispensable task from an environmental point of view to recover the freon gases from the air conditioners of automobiles, from the household electric refrigerators, from the household air conditioners and from the refrigerated show cases, that have relatively short service lives.
Therefore, a variety kinds of coolant recovering devices have been placed in the market using an electric motor or an auxiliary engine as a drive source.
However, these devices are generally expensive compared to their recovering ability and have not been widely used, since people who dismantle the automobiles on business and people who dismantle the household electric appliances on business are reluctant to buy such devices.
Therefore, considerably large amounts of freon gases have presumably been released into the air though people in charge of the task may be considering it not desirable from the standpoint of environment.
To cope with these problems, a method and an apparatus for recovering freon gas have been proposed as disclosed in, for example, Japanese Unexamined Patent Publication (Kokai) No. 2995/1994. This method, however, uses a compressor that is driven by an engine of a vehicle that is going to recover the freon gas. The compressor of a vehicle from which the freon gas is to be recovered is not driven. Accordingly, fuel remaining in the vehicle from which the freon gas is to be recovered is not consumed, and the distance inevitably increases between the refrigerator circuit in the vehicle from which to recover and the compressor of the vehicle that is going to recover; i.e., the coolant is not highly efficiently recovered within short periods of time. The same holds even for the electric refrigerators, air conditioners, refrigerated show cases, etc.
When the compressor of the vehicle from which the coolant is to be recovered is driven according to the prior art, the condenser in the refrigerator circuit and the fan of the indoor evaporator in the vehicle from which to recover are not driven when the atmospheric temperature is low (e.g., -10.degree. C.). In other words, there is no endothermic action in the indoor evaporator, the coolant is not heated and the receiver tank is frozen. Therefore, the coolant does not flow and is not recovered despite the compressor of the vehicle from which to recover is driven or despite the coolant is sucked utilizing the negative pressure produced by the compressor of the vehicle that is going to recover.
The present inventors therefore have conducted keen study, have learned that a highly efficient method of recovering the coolant at a low cost can be realized by temporarily driving the compressor included in the air conditioner or in the refrigerator circuit in the apparatus from which the coolant is to be recovered, such as cars or refrigerators out of service, and have arrived at the present invention.
So far, furthermore, there has been employed a three-way valve for recovering a pressurized fluid, wherein a coupler is connected to discharge the pressurized fluid out of the pressurized fluid circuit such as a refrigerator circuit, the three-way valve communicating the interior of the refrigerator circuit from which to recover with the exterior of the circuit. The three-way valve is normally closed but is opened for the first time upon connecting the coupler. In this case, the coupler that is connected is equipped with an automatic stop valve even on the side of the circuit from which to recover, in order to prevent the pressurized fluid from flowing into the environment. However, the coupler has boon designed to be connected through one-touch operation and has also been designed to be disconnected through one-touch operation by simply moving the sleeve with a finger toward the direction of disconnection, leaving such a probability that the coupler in a connected state may be inadvertently and undesirably disconnected.
Accordingly, there has been proposed a highly safe coupler incorporating a double-lock mechanism which does not permit the coupler to be disconnected despite the sleeve is simply moved in the direction of disconnection, as disclosed in, for example, Japanese Unexamined Patent Publication (Kokai) No. 68292/1997.
However, there has not yet been known a three-way valve for recovering a pressurized fluid, which is disposed in the pressurized fluid circuit and which is opened to the recovery circuit through one-touch operation as the coupler molded integrally therewith is connected.
So far, therefore, a double action is required, i.e., a manually operated three-way valve is provided for the pressurized fluid circuit and is, then, opened to the recovery circuit after the coupler is connected.
It may appear that the double action is not much of a work. To carry out the "method of recovering a coolant, apparatus therefor and tool therefor" of the present invention by using a conventional three-way valve, however, the three-way valve is closed, first, and then the coupler is connected (which is usually the way it is). In this case, the compressor does not readily come into a halt, and the pressure of the fluid suddenly rises. In the worst case, the refrigerator circuit in ruptured. Therefore, the three-way valve must be operated simultaneously with the connection of the coupler, which, however, could not be accomplished with the conventional combination of the three-way valve and the coupler that were independent from each other.